From the Guidelines
Metabolic alkalosis should be treated by addressing the underlying cause, correcting fluid and electrolyte imbalances, and using therapies such as normal saline, potassium chloride, and acetazolamide as needed, with the goal of normalizing pH and addressing the underlying pathophysiology. When treating metabolic alkalosis, it is crucial to identify and eliminate the cause, such as stopping diuretics like frusemide, which can cause severe electrolyte disturbances and metabolic alkalosis at high doses 1. For mild cases, oral rehydration with normal saline (0.9% NaCl) is often sufficient, while in severe cases (pH > 7.55 or bicarbonate > 40 mEq/L), intravenous normal saline at 100-200 mL/hour should be administered to restore intravascular volume and promote bicarbonate excretion. Key considerations include:
- Potassium chloride supplementation (typically 20-40 mEq IV or oral supplements) if hypokalemia is present, as potassium correction helps shift hydrogen ions extracellularly
- Providing chloride to allow the kidneys to excrete excess bicarbonate in cases of chloride-responsive alkalosis
- Using acetazolamide (250-500 mg orally every 6 hours) in refractory cases to increase bicarbonate excretion, though this should be used cautiously in volume-depleted patients
- Administering dilute hydrochloric acid (0.1-0.2 N HCl) through a central venous catheter in severe, life-threatening alkalosis unresponsive to other measures, with intensive monitoring. Treatment effectiveness should be assessed through serial arterial blood gas measurements and electrolyte panels, with the goal of normalizing pH while addressing the underlying pathophysiology that disrupted acid-base balance.
From the FDA Drug Label
When the intake of the chloride ion is less than is excreted, there is a relative increase in the blood bicarbonate level, producing the condition known as alkalosis. The treatment for metabolic alkalosis is not directly stated in the label, but it can be inferred that replenishing chloride ions may help alleviate the condition.
- The label mentions that a relative increase in blood bicarbonate level produces alkalosis when the intake of chloride ion is less than excreted.
- It also mentions that sodium chloride (IV) can be used to replenish sodium and chloride ions in the body. However, the label does not provide explicit treatment guidelines for metabolic alkalosis. 2
From the Research
Treatment of Metabolic Alkalosis
- The treatment of metabolic alkalosis is usually supportive and based on the cause of the alkalosis 3
- Conventional conservative treatment involves meeting the patient's fluid and electrolyte needs and allowing the body to correct the alkalosis through its own mechanisms 4
- In cases where more rapid resolution of the alkalosis is needed or the patient cannot tolerate fluid and electrolyte therapy, mineral acids may be administered 4
- Mineral acid administration options include:
- The primary drug of choice for patients requiring mineral acid administration is intravenous ammonium chloride, while patients with hepatic or severe renal dysfunction should receive dilute hydrochloric acid via a central-venous catheter 4
- Other possible therapeutic alternatives include dialysis, acetazolamide, and cimetidine 4
- The cornerstone of treatment is the correction of existing depletions and the prevention of further losses, such as infusion of potassium chloride to restore the excretion of bicarbonate by the kidney in vomiting-induced chloride depletion alkalosis 6
Factors to Consider in Treatment
- Volume contraction, low glomerular filtration rate, potassium deficiency, hypochloremia, aldosterone excess, and elevated arterial carbon dioxide can impair the ability of the kidney to eliminate excess bicarbonate, promoting the generation or impairing the correction of metabolic alkalosis 7
- Evaluation of volemic status and measurement of urinary Cl- and plasma levels of renin and aldosterone are crucial to identify the cause(s) of metabolic alkalosis 6